Although the first mutation associated with Parkinson's disease (PD) was identified sever... more Although the first mutation associated with Parkinson's disease (PD) was identified several years ago in the alpha-synuclein (SNCA) gene in families of Greek and Italian ancestry, a more systematic study of this and other known PD mutations has not been performed in the Greek population. A genetic analysis in 111 familial or sporadic with early-onset (≤50 years, EO) PD patients was performed for the presence of the A53T SNCA mutation. In separate subgroups of these patients, further mutations in the SNCA, LRRK2, Parkin, PINK1 and DJ-1 genes were searched for. Additionally, a subgroup of familial cases was analysed for mutations in the glucocerebrosidase (GBA) gene. In total, five patients (4.5% of our whole population) were identified with the A53T SNCA mutation, two with a heterozygote dosage mutation and one with a heterozygote point mutation in the Parkin gene, and seven patients (10.3% of our familial cohort) with GBA gene mutations. The A53T mutation in the SNCA gene, although uncommon, does represent a cause of PD in the Greek population, especially of familial EOPD with autosomal dominant inheritance. GBA mutations in the familial cohort tested here were as common as in a cohort of sporadic cases previously examined from the same centres. For the remainder of the genes, genetic defects that could definitively account for the disease were not identified. These results suggest that further Mendelian traits that lead to PD in the Greek population remain to be identified.
We aim to clarify the pathogenic role of intermediate size repeat expansions of SCA2, SCA3, SCA6,... more We aim to clarify the pathogenic role of intermediate size repeat expansions of SCA2, SCA3, SCA6, and SCA17 as risk factors for idiopathic Parkinson disease (PD). We invited researchers from the Genetic Epidemiology of Parkinson's Disease Consortium to participate in the study. There were 12,346 cases and 8,164 controls genotyped, for a total of 4 repeats within the SCA2, SCA3, SCA6, and SCA17 genes. Fixed- and random-effects models were used to estimate the summary risk estimates for the genes. We investigated between-study heterogeneity and heterogeneity between different ethnic populations. We did not observe any definite pathogenic repeat expansions for SCA2, SCA3, SCA6, and SCA17 genes in patients with idiopathic PD from Caucasian and Asian populations. Furthermore, overall analysis did not reveal any significant association between intermediate repeats and PD. The effect estimates (odds ratio) ranged from 0.93 to 1.01 in the overall cohort for the SCA2, SCA3, SCA6, and SCA...
Anti-basal ganglia antibodies (ABGA) are associated with movement disorders in children, but have... more Anti-basal ganglia antibodies (ABGA) are associated with movement disorders in children, but have not been assessed in adult onset movement disorders. In a prospective assessment ABGA were positive in 65% of a group of 65 patients with atypical movement disorders, but were very rare in healthy adults and adults with idiopathic dystonia. An autoimmune mechanism may underlie a proportion of cases of atypical movement disorders.
Xiromerisiou, G., Kyratzi, E., Dardiotis, E., Bozi, M., Tsimourtou, V., Stamboulis, E., Ralli, S.... more Xiromerisiou, G., Kyratzi, E., Dardiotis, E., Bozi, M., Tsimourtou, V., Stamboulis, E., Ralli, S., Vassilatis, D., Gourbali, V., Kountra, P.-M., Fountas, K., Papadimitriou, A., Stefanis, L. and Hadjigeorgiou, GM (2011), Lack of Association of the UCHL-1 gene with Parkinson's ...
We aim to clarify the pathogenic role of intermediate size repeat expansions of SCA2, SCA3, SCA6,... more We aim to clarify the pathogenic role of intermediate size repeat expansions of SCA2, SCA3, SCA6, and SCA17 as risk factors for idiopathic Parkinson disease (PD). We invited researchers from the Genetic Epidemiology of Parkinson's Disease Consortium to participate in the study. There were 12,346 cases and 8,164 controls genotyped, for a total of 4 repeats within the SCA2, SCA3, SCA6, and SCA17 genes. Fixed- and random-effects models were used to estimate the summary risk estimates for the genes. We investigated between-study heterogeneity and heterogeneity between different ethnic populations. We did not observe any definite pathogenic repeat expansions for SCA2, SCA3, SCA6, and SCA17 genes in patients with idiopathic PD from Caucasian and Asian populations. Furthermore, overall analysis did not reveal any significant association between intermediate repeats and PD. The effect estimates (odds ratio) ranged from 0.93 to 1.01 in the overall cohort for the SCA2, SCA3, SCA6, and SCA...
Psychotic features in patients with Parkinson&amp... more Psychotic features in patients with Parkinson's Disease usually present as visual hallucinations against a background of cognitive deterioration and dopaminomimetic therapy. Isolated delusions are rare. We report here 4 patients with Parkinson's Disease who developed a delusional syndrome resembling schizophreniform psychosis in the absence of changes in alertness, visual hallucinations or dementia. We suggest that this syndrome may be more common than previously recognized, and that it may be related to the use of dopaminergic medications and environmental triggers on a background of a susceptible individual. This syndrome suggests interesting parallels with the pathophysiology of amphetamine-induced psychosis and schizophrenia.
Xiromerisiou, G., Kyratzi, E., Dardiotis, E., Bozi, M., Tsimourtou, V., Stamboulis, E., Ralli, S.... more Xiromerisiou, G., Kyratzi, E., Dardiotis, E., Bozi, M., Tsimourtou, V., Stamboulis, E., Ralli, S., Vassilatis, D., Gourbali, V., Kountra, P.-M., Fountas, K., Papadimitriou, A., Stefanis, L. and Hadjigeorgiou, GM (2011), Lack of Association of the UCHL-1 gene with Parkinson's ...
An increasing number of clinical, neuropathological and experimental evidence linking Gaucher dis... more An increasing number of clinical, neuropathological and experimental evidence linking Gaucher disease and a spectrum of synucleinopathies, including Parkinson's disease (PD) has emerged over the last decade. In particular, several studies, despite individual differences, have shown that mutations in the β-glucocerebrosidase gene (GBA) are a risk factor for PD. Recently a study from Northern Greece has shown a significant overrepresentation of such mutations only in patients with early onset PD. In the present study 8 different GBA mutations covering 87% of the mutations identified in Gaucher disease patients diagnosed in Greece were investigated in two ethnic Greek cohorts of patients with sporadic Parkinson's disease. Cohort A included patients residing and originating from Thessaly, Central Greece (n=100) and cohort B included patients residing and/or originating from the greater area of Athens (n=105). Age-gender-ethnicity matched healthy individuals from the same areas were included as controls (n=206). In patients of cohort A 11 carriers of GBA mutations were identified (5/11:N370S, 2/11:L444P, 2/11: D409H;H255Q, 1/11:H255Q, 1/11D409H) as opposed to 3 in the controls (n=105) (1/3:N370S, 1/3:H255Q, 1/3:Y108C) (p=0.021, OR 4.2, 95% CI=1.14-15.54). In patients of cohort B 10 carriers of GBA mutations were identified (4/10:L444P, 4/10:D409H;H255Q, 1/10:N370S, 1/10:IVS10-1G→A) as opposed to 4 in controls (n=101) (3/4:N370S, 1/4:L444P). However the difference was not statistically significant (p=0.113, OR 2.5, 95% CI=0.77-8.42). In both cohorts, patients with PD harboring a GBA mutation had an earlier onset of symptoms than non-carriers (p=0.034, p=0.004). The overall difference in the number of carriers identified in PD patients and controls was statistically significant (p=0.006; OR 3.24; 95% CI=1.35-7.81). The association was reinforced in the early onset PD patients (EOPD; n=28, p=0.000, OR 11.37; 95% CI=3.73-34.6). In conclusion GBA mutations were identified with increased frequency in both geographical cohorts of patients with sporadic PD studied compared to control individuals, with the difference being statistically significant only in cohort A. An impressive association with EOPD was found and one third of the EOPD patients examined harbored a GBA mutation. Qualitative differences regarding the type of mutations and/or their relative frequencies were observed between cohorts A and B of PD patients. Genetic and/or environmental factors may account for the observed differences.
Background The leucine-rich repeat kinase 2 gene (LRRK2) harbours highly penetrant mutations that... more Background The leucine-rich repeat kinase 2 gene (LRRK2) harbours highly penetrant mutations that are linked to familial parkinsonism. However, the extent of its polymorphic variability in relation to risk of Parkinson's disease (PD) has not been assessed systematically. We therefore assessed the frequency of LRRK2 exonic variants in individuals with and without PD, to investigate the role of the variants in PD susceptibility. LRRK2 was genotyped in patients with PD and controls from three series (white, Asian, and Arab-Berber) from sites participating in the Genetic Epidemiology of Parkinson's Disease Consortium. Genotyping was done for exonic variants of LRRK2 that were identified through searches of literature and the personal communications of consortium members. Associations with PD were assessed by use of logistic regression models. For variants that had a minor allele frequency of 0·5% or greater, single variant associations were assessed, whereas for rarer variants information was collapsed across variants. 121 exonic LRRK2 variants were assessed in 15 540 individuals: 6995 white patients with PD and 5595 controls, 1376 Asian patients and 962 controls, and 240 Arab-Berber patients and 372 controls. After exclusion of carriers of known pathogenic mutations, new independent risk associations were identified for polymorphic variants in white individuals (M1646T, odds ratio 1·43, 95% CI 1·15-1·78; p=0·0012) and Asian individuals (A419V, 2·27, 1·35-3·83; p=0·0011). A protective haplotype (N551K-R1398H-K1423K) was noted at a frequency greater than 5% in the white and Asian series, with a similar finding in the Arab-Berber series (combined odds ratio 0·82, 0·72-0·94; p=0·0043). Of the two previously reported Asian risk variants, G2385R was associated with disease (1·73, 1·20-2·49; p=0·0026), but no association was noted for R1628P (0·62, 0·36-1·07; p=0·087). In the Arab-Berber series, Y2189C showed potential evidence of risk association with PD (4·48, 1·33-15·09; p=0·012). The results for LRRK2 show that several rare and common genetic variants in the same gene can have independent effects on disease risk. LRRK2, and the pathway in which it functions, is important in the cause and pathogenesis of PD in a greater proportion of patients with this disease than previously believed. These results will help discriminate those patients who will benefit most from therapies targeted at LRRK2 pathogenic activity.…
Although the first mutation associated with Parkinson's disease (PD) was identified sever... more Although the first mutation associated with Parkinson's disease (PD) was identified several years ago in the alpha-synuclein (SNCA) gene in families of Greek and Italian ancestry, a more systematic study of this and other known PD mutations has not been performed in the Greek population. A genetic analysis in 111 familial or sporadic with early-onset (≤50 years, EO) PD patients was performed for the presence of the A53T SNCA mutation. In separate subgroups of these patients, further mutations in the SNCA, LRRK2, Parkin, PINK1 and DJ-1 genes were searched for. Additionally, a subgroup of familial cases was analysed for mutations in the glucocerebrosidase (GBA) gene. In total, five patients (4.5% of our whole population) were identified with the A53T SNCA mutation, two with a heterozygote dosage mutation and one with a heterozygote point mutation in the Parkin gene, and seven patients (10.3% of our familial cohort) with GBA gene mutations. The A53T mutation in the SNCA gene, although uncommon, does represent a cause of PD in the Greek population, especially of familial EOPD with autosomal dominant inheritance. GBA mutations in the familial cohort tested here were as common as in a cohort of sporadic cases previously examined from the same centres. For the remainder of the genes, genetic defects that could definitively account for the disease were not identified. These results suggest that further Mendelian traits that lead to PD in the Greek population remain to be identified.
Although the first mutation associated with Parkinson's disease (PD) was identified sever... more Although the first mutation associated with Parkinson's disease (PD) was identified several years ago in the alpha-synuclein (SNCA) gene in families of Greek and Italian ancestry, a more systematic study of this and other known PD mutations has not been performed in the Greek population. A genetic analysis in 111 familial or sporadic with early-onset (≤50 years, EO) PD patients was performed for the presence of the A53T SNCA mutation. In separate subgroups of these patients, further mutations in the SNCA, LRRK2, Parkin, PINK1 and DJ-1 genes were searched for. Additionally, a subgroup of familial cases was analysed for mutations in the glucocerebrosidase (GBA) gene. In total, five patients (4.5% of our whole population) were identified with the A53T SNCA mutation, two with a heterozygote dosage mutation and one with a heterozygote point mutation in the Parkin gene, and seven patients (10.3% of our familial cohort) with GBA gene mutations. The A53T mutation in the SNCA gene, although uncommon, does represent a cause of PD in the Greek population, especially of familial EOPD with autosomal dominant inheritance. GBA mutations in the familial cohort tested here were as common as in a cohort of sporadic cases previously examined from the same centres. For the remainder of the genes, genetic defects that could definitively account for the disease were not identified. These results suggest that further Mendelian traits that lead to PD in the Greek population remain to be identified.
We aim to clarify the pathogenic role of intermediate size repeat expansions of SCA2, SCA3, SCA6,... more We aim to clarify the pathogenic role of intermediate size repeat expansions of SCA2, SCA3, SCA6, and SCA17 as risk factors for idiopathic Parkinson disease (PD). We invited researchers from the Genetic Epidemiology of Parkinson's Disease Consortium to participate in the study. There were 12,346 cases and 8,164 controls genotyped, for a total of 4 repeats within the SCA2, SCA3, SCA6, and SCA17 genes. Fixed- and random-effects models were used to estimate the summary risk estimates for the genes. We investigated between-study heterogeneity and heterogeneity between different ethnic populations. We did not observe any definite pathogenic repeat expansions for SCA2, SCA3, SCA6, and SCA17 genes in patients with idiopathic PD from Caucasian and Asian populations. Furthermore, overall analysis did not reveal any significant association between intermediate repeats and PD. The effect estimates (odds ratio) ranged from 0.93 to 1.01 in the overall cohort for the SCA2, SCA3, SCA6, and SCA...
Anti-basal ganglia antibodies (ABGA) are associated with movement disorders in children, but have... more Anti-basal ganglia antibodies (ABGA) are associated with movement disorders in children, but have not been assessed in adult onset movement disorders. In a prospective assessment ABGA were positive in 65% of a group of 65 patients with atypical movement disorders, but were very rare in healthy adults and adults with idiopathic dystonia. An autoimmune mechanism may underlie a proportion of cases of atypical movement disorders.
Xiromerisiou, G., Kyratzi, E., Dardiotis, E., Bozi, M., Tsimourtou, V., Stamboulis, E., Ralli, S.... more Xiromerisiou, G., Kyratzi, E., Dardiotis, E., Bozi, M., Tsimourtou, V., Stamboulis, E., Ralli, S., Vassilatis, D., Gourbali, V., Kountra, P.-M., Fountas, K., Papadimitriou, A., Stefanis, L. and Hadjigeorgiou, GM (2011), Lack of Association of the UCHL-1 gene with Parkinson's ...
We aim to clarify the pathogenic role of intermediate size repeat expansions of SCA2, SCA3, SCA6,... more We aim to clarify the pathogenic role of intermediate size repeat expansions of SCA2, SCA3, SCA6, and SCA17 as risk factors for idiopathic Parkinson disease (PD). We invited researchers from the Genetic Epidemiology of Parkinson's Disease Consortium to participate in the study. There were 12,346 cases and 8,164 controls genotyped, for a total of 4 repeats within the SCA2, SCA3, SCA6, and SCA17 genes. Fixed- and random-effects models were used to estimate the summary risk estimates for the genes. We investigated between-study heterogeneity and heterogeneity between different ethnic populations. We did not observe any definite pathogenic repeat expansions for SCA2, SCA3, SCA6, and SCA17 genes in patients with idiopathic PD from Caucasian and Asian populations. Furthermore, overall analysis did not reveal any significant association between intermediate repeats and PD. The effect estimates (odds ratio) ranged from 0.93 to 1.01 in the overall cohort for the SCA2, SCA3, SCA6, and SCA...
Psychotic features in patients with Parkinson&amp... more Psychotic features in patients with Parkinson's Disease usually present as visual hallucinations against a background of cognitive deterioration and dopaminomimetic therapy. Isolated delusions are rare. We report here 4 patients with Parkinson's Disease who developed a delusional syndrome resembling schizophreniform psychosis in the absence of changes in alertness, visual hallucinations or dementia. We suggest that this syndrome may be more common than previously recognized, and that it may be related to the use of dopaminergic medications and environmental triggers on a background of a susceptible individual. This syndrome suggests interesting parallels with the pathophysiology of amphetamine-induced psychosis and schizophrenia.
Xiromerisiou, G., Kyratzi, E., Dardiotis, E., Bozi, M., Tsimourtou, V., Stamboulis, E., Ralli, S.... more Xiromerisiou, G., Kyratzi, E., Dardiotis, E., Bozi, M., Tsimourtou, V., Stamboulis, E., Ralli, S., Vassilatis, D., Gourbali, V., Kountra, P.-M., Fountas, K., Papadimitriou, A., Stefanis, L. and Hadjigeorgiou, GM (2011), Lack of Association of the UCHL-1 gene with Parkinson's ...
An increasing number of clinical, neuropathological and experimental evidence linking Gaucher dis... more An increasing number of clinical, neuropathological and experimental evidence linking Gaucher disease and a spectrum of synucleinopathies, including Parkinson's disease (PD) has emerged over the last decade. In particular, several studies, despite individual differences, have shown that mutations in the β-glucocerebrosidase gene (GBA) are a risk factor for PD. Recently a study from Northern Greece has shown a significant overrepresentation of such mutations only in patients with early onset PD. In the present study 8 different GBA mutations covering 87% of the mutations identified in Gaucher disease patients diagnosed in Greece were investigated in two ethnic Greek cohorts of patients with sporadic Parkinson's disease. Cohort A included patients residing and originating from Thessaly, Central Greece (n=100) and cohort B included patients residing and/or originating from the greater area of Athens (n=105). Age-gender-ethnicity matched healthy individuals from the same areas were included as controls (n=206). In patients of cohort A 11 carriers of GBA mutations were identified (5/11:N370S, 2/11:L444P, 2/11: D409H;H255Q, 1/11:H255Q, 1/11D409H) as opposed to 3 in the controls (n=105) (1/3:N370S, 1/3:H255Q, 1/3:Y108C) (p=0.021, OR 4.2, 95% CI=1.14-15.54). In patients of cohort B 10 carriers of GBA mutations were identified (4/10:L444P, 4/10:D409H;H255Q, 1/10:N370S, 1/10:IVS10-1G→A) as opposed to 4 in controls (n=101) (3/4:N370S, 1/4:L444P). However the difference was not statistically significant (p=0.113, OR 2.5, 95% CI=0.77-8.42). In both cohorts, patients with PD harboring a GBA mutation had an earlier onset of symptoms than non-carriers (p=0.034, p=0.004). The overall difference in the number of carriers identified in PD patients and controls was statistically significant (p=0.006; OR 3.24; 95% CI=1.35-7.81). The association was reinforced in the early onset PD patients (EOPD; n=28, p=0.000, OR 11.37; 95% CI=3.73-34.6). In conclusion GBA mutations were identified with increased frequency in both geographical cohorts of patients with sporadic PD studied compared to control individuals, with the difference being statistically significant only in cohort A. An impressive association with EOPD was found and one third of the EOPD patients examined harbored a GBA mutation. Qualitative differences regarding the type of mutations and/or their relative frequencies were observed between cohorts A and B of PD patients. Genetic and/or environmental factors may account for the observed differences.
Background The leucine-rich repeat kinase 2 gene (LRRK2) harbours highly penetrant mutations that... more Background The leucine-rich repeat kinase 2 gene (LRRK2) harbours highly penetrant mutations that are linked to familial parkinsonism. However, the extent of its polymorphic variability in relation to risk of Parkinson's disease (PD) has not been assessed systematically. We therefore assessed the frequency of LRRK2 exonic variants in individuals with and without PD, to investigate the role of the variants in PD susceptibility. LRRK2 was genotyped in patients with PD and controls from three series (white, Asian, and Arab-Berber) from sites participating in the Genetic Epidemiology of Parkinson's Disease Consortium. Genotyping was done for exonic variants of LRRK2 that were identified through searches of literature and the personal communications of consortium members. Associations with PD were assessed by use of logistic regression models. For variants that had a minor allele frequency of 0·5% or greater, single variant associations were assessed, whereas for rarer variants information was collapsed across variants. 121 exonic LRRK2 variants were assessed in 15 540 individuals: 6995 white patients with PD and 5595 controls, 1376 Asian patients and 962 controls, and 240 Arab-Berber patients and 372 controls. After exclusion of carriers of known pathogenic mutations, new independent risk associations were identified for polymorphic variants in white individuals (M1646T, odds ratio 1·43, 95% CI 1·15-1·78; p=0·0012) and Asian individuals (A419V, 2·27, 1·35-3·83; p=0·0011). A protective haplotype (N551K-R1398H-K1423K) was noted at a frequency greater than 5% in the white and Asian series, with a similar finding in the Arab-Berber series (combined odds ratio 0·82, 0·72-0·94; p=0·0043). Of the two previously reported Asian risk variants, G2385R was associated with disease (1·73, 1·20-2·49; p=0·0026), but no association was noted for R1628P (0·62, 0·36-1·07; p=0·087). In the Arab-Berber series, Y2189C showed potential evidence of risk association with PD (4·48, 1·33-15·09; p=0·012). The results for LRRK2 show that several rare and common genetic variants in the same gene can have independent effects on disease risk. LRRK2, and the pathway in which it functions, is important in the cause and pathogenesis of PD in a greater proportion of patients with this disease than previously believed. These results will help discriminate those patients who will benefit most from therapies targeted at LRRK2 pathogenic activity.…
Although the first mutation associated with Parkinson's disease (PD) was identified sever... more Although the first mutation associated with Parkinson's disease (PD) was identified several years ago in the alpha-synuclein (SNCA) gene in families of Greek and Italian ancestry, a more systematic study of this and other known PD mutations has not been performed in the Greek population. A genetic analysis in 111 familial or sporadic with early-onset (≤50 years, EO) PD patients was performed for the presence of the A53T SNCA mutation. In separate subgroups of these patients, further mutations in the SNCA, LRRK2, Parkin, PINK1 and DJ-1 genes were searched for. Additionally, a subgroup of familial cases was analysed for mutations in the glucocerebrosidase (GBA) gene. In total, five patients (4.5% of our whole population) were identified with the A53T SNCA mutation, two with a heterozygote dosage mutation and one with a heterozygote point mutation in the Parkin gene, and seven patients (10.3% of our familial cohort) with GBA gene mutations. The A53T mutation in the SNCA gene, although uncommon, does represent a cause of PD in the Greek population, especially of familial EOPD with autosomal dominant inheritance. GBA mutations in the familial cohort tested here were as common as in a cohort of sporadic cases previously examined from the same centres. For the remainder of the genes, genetic defects that could definitively account for the disease were not identified. These results suggest that further Mendelian traits that lead to PD in the Greek population remain to be identified.
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